As this type of apparatus, there has been suggested an apparatus for preventing an exhaust changeover valve from sticking (e.g. refer to a patent document 1). According to an abnormality prevention controller of an engine with a supercharger disclosed in the patent document 1, if a valve stick state is predicted by a valve stick state predicting device on the basis of the quantity of state or the operating condition of an engine and a system, the exhaust changeover valve is forcibly driven. Thus, next time the exhaust changeover valve is closed, a contact position between a valve outer circumferential portion and a housing inner circumferential portion changes, so that the valve stick is prevented.
Incidentally, the technique for suppressing the sticking by forcibly driving the exhaust changeover valve is also disclosed in for example a patent document 2.
Moreover, there has been also suggested a technique for suppressing the sticking in a fully-opened or fully-closed state by controlling the exhaust changeover valve and a WGV to have a predetermined intermediate opening degree at the time of engine stop (e.g. refer to a patent document 3).
Patent document 1: Japanese Patent Application Laid Open No. Hei 4-47125
Patent document 2: Japanese Patent Application Laid Open No. Hei 5-272344
Patent document 3: Japanese Patent Application Laid Open No. 2008-180176